1. Digital Television based on the MPEG-2 Standard

2. Overview MPEG-2 Digital TV DVB PSI tables structure
Digital TV Distribution System
The MHP system

3. MPEG History
Moving Picture Experts Group was founded in January 1988 by Leonardo Chiariglione together with around 15 experts in compression technology
Creator of numerous standards like MPEG-1, MPEG-2, MPEG-4, MPEG-7, MPEG-21 etc.
The Group has not limited it’s scope to only “pictures” – sound wasn’t forgot (e.g. MPEG-1 Layer3)
Because almost all of their work is a success story, the industry adopted fast the MPEG standard (Philips, Samsung, Intel, Sony etc)
MPEG has given birth to a number of technologies we take now for granted: DVD and Digital TV (MPEG-2), MP3 (MPEG-1 L3)

4. MPEG-2
In 1994, MPEG has published the ISO/IEC-13818, also known as MPEG-2
MPEG-2 was the standard adopted by DVD (Digital Video Disk or Digital Versatile Disk) and Digital TV
It is designed for video compression between 1.5 and 15 Mbps
MPEG-2 streams come in 2 forms: Program Stream and Transport Stream

5. Digital TV Why use Digital TV instead of Analog TV?
ease of transcoding (changing the same perceptual content by decreasing quality, but with great gains in bitrate)
ease of storing data for future use and reprocessing
no quality loss (digitized information does not ”change” in time)
ability to supply more services (like MHP, EPG etc)
better and more flexible protection system in commercial TV (encoded channels)
It has been discovered that there are more television sets than telephones in the world – huge market
The video and audio information is digitized and compressed using the MPEG compression standard (source coding)
There are presently three international standards for digital television
Digital Video Broadcasting (DVB)
Advanced Television Systems Committee (ATSC)
Integrated Services Digital Broadcasting (ISDB)

6. Digital TV Standards Adoption Map

7. Model for MPEG-2 Systems

8. MPEG-2 Program Stream Similar to MPEG-1 Systems Multiplex
Combines one or more Packetised Elementary Streams (PES), which have a common time-base, into a single stream
Designed for use in relatively error-free environments and suitable for applications which may involve software processing
Program stream packets may be of variable and relatively great length

9. MPEG-2 Transport Stream
Combines one or more Packetised Elementary Streams (PES) with one or more independent time bases into a single stream (sometimes called multiplex)
Elementary streams sharing a common time-base form a program
Designed for use in environments where errors are likely, such as storage or transmission in lossy or noisy media
The transport stream is made of packets with fixed length of 188 bytes

10. Packets are idenitifed by PID’s
PID= Packet IDentifier, for video, audio
and other data: Example: satellite transmission parameters
Number of QPSK symbols/sec
Error correction rate
Program idenitification number
Frequency,
polarisation
Video PID
Audio PID

11. The Transport Stream Packet

12. DVB DVB Project is an industry-led consortium of over 300 companies
The DVB Project was launched on 10th September, 1993
In 1995 it was basically finished and became operational
There are several sub-standards of the DVB standard
DVB-S (Satellite) – using QPSK – 40 Mb/s
DVB-T (Terrestrial) – using QAM – 50 Mb/s
DVB-C (Cable) – using OFDM – 24 Mb/s
These three sub-standards basically differ only in the specifications to the physical representation, modulation, transmission and reception of the signal

13. About DVB Standard
DVB uses the MPEG-2 Transport Stream to carry it’s data
DVB has added some features in the MPEG-2 standard (the MPEG standard had a door open for future additions to the standard)
Can deliver to the home almost anything that can be digitized:
High Definition Television (HDTV)
Standard Definition Television (PAL / NTSC, SECAM)
New broadband multimedia data and interactive services
Several tables have been added to the MPEG-2 Transport Stream specifications (CAT, EIT etc)

14. The MPEG-2/DVB Multiplex
A multiplex is a bouquet of PIDs containing several channels (television, radio, data etc), basically is a collection of programs
This bouquet contains several types of information (audio data, video data) and a Program Specific Information (PSI) section made of tables containing the description of the contents
Based on the PSI, the decoders can select the correct PIDs of the desired program in order to decode them
All the programs present in the multiplex have different PIDs for their data (audio, video, pcr, subtitle, teletext etc)

15. DVB Service Information
DVB-SI provides information to enable automatic configuration of the receiver to demultiplex and decode the various streams of programs within the multiplex
Program Specific Information (PSI)
Program Association Table (PAT): for each service in the multiplex, the PAT indicates the location (the PID values of the TS packets) of the corresponding PMT. It also gives the location of the NIT
Conditional Access Table (CAT): provides information on the CA systems used in the multiplex; the information is private and dependent on the CA system
Program Map Table (PMT): identifies and indicates the locations of the streams that make up each service, and the location of the Program Clock Reference fields for a service
Network Information Table (NIT): provides information about the physical network
Additional Service Information
Bouquet Association Table (BAT): provides information regarding bouquets
Service Description Table (SDT): describes the services in the system e.g. names of services, the service provider, etc
Event Information Table (EIT): contains data concerning events or programs such as event name, start time, duration, etc
Running Status Table (RST): gives the status of an event (running / not running)
Other tables: TDT, TOT, ST, SIT, DIT

16. MPEG-2/DVB PID Allocation
PAT always has PID = 0 (zero)
CAT always has PID = 1
EIT always has PID = 18
The PMTs have the PIDs specified in the PAT
The audio, video, PCR, subtitle, teletext etc PIDs for all programs are specified in their respective PMT

17. MPEG-2/DVB PSI Structure

18. DVB Subtitles Are carried in PES (themselves being carried in TS)
Timing of presentation is the PTS of the PES (present in the PES header)
Information is transmitted in graphical format
Pixel depths of 2, 4 and 8 bits are supported
Color information is organized in Color Look-Up Tables (CLUT)
Subtitles are present in a sequence of pages that are going to be overlayed on the associated video image
A subtitle page contains one or more regions (rectangular areas with specified sets of attributes: position, width, height, depth etc)
Several regions can be used at the same time (i.e. one region in the bottom of the screen displaying the subtitle, another in one somewhere else on the screen displaying some logo)
There are different events
page update (when only the changed regions from previous page are present)
page refresh (when all the data needed to display the page is present)

19. The Packetised Elementary Stream Packet

20. PAT Structure table_id (= 0x00) section_syntax_indicator marker_bit
reserved (2 bits)
section_length
transport_stream_id
version_number
current_next_indicator
section_number
last_section_number
network_PID
yes no
program_number
reserved (3 bits)
program_number = 0 ?
finished? no
yes
TS_program_map_table_PID
CRC_32
stuffing_bytes_to_end_of_TS_packet

21. CAT Structure table_id (= 0x01) section_syntax_indicator marker_bit
reserved (2 bits)
section_length
reserved (18 bits)
version_number
current_next_indicator
section_number
last_section_number no
descriptor_tag (=9)
descriptor_length
CA_system_ID
reserved (3 bits)
CA_PID
private_data_bytes
finished?
CRC_32
yes
stuffing_bytes_to_end_of_TS_packet

22. PMT Structure table_id (= 0x02) section_syntax_indicator
marker_bit ‘0’
reserved_bits (2 bits)
section_length
program_number
version_number
current_next_indicator
section_number (=0)
last_section_number (=0)
reserved_bits (3 bits)
PCR_PID
reserved_bits (4 bits)
program_info_length
program_descriptors()
stream_type
reserved (3 bits)
elementary_PID
ES_info_length
ES_descriptors() no
finished?
yes
CRC_32
stuffing_bytes_to_end_of_TS_packet

23. What is MHP

24. FOR MULTIMEDIA ORIGINATING FROM DIGITAL TELEVISION
APPLICATION DEVELOPMENT
PLATFORM IS MHP – MULTIMEDIA
HOME PLATFORM DEVELOPED
BY EUROPEAN DVB ORGANISATION
IT WAS ACCEPTED FOR NORDIC COUNTRIES IN MARCH 2001

25. DVB in the home
DVB – Digital Video Broadcasting, covers digital TV delivery
by S - satellite, C- cable and T- terrestrial plus networking
DVB-S
DVB-MS
DVB-MC
SDTV / EDTV / HDTV
Integrated Receiver-
Decoder (IRD)
DVB-C PC
DVB-T
B-ISDN, ASDL,
PSTN, GSM
DVD
DVC

26. The Uses of DVB - a Scenario
Cable / (S)MATV
Terrestrial
TV Receiver Multimedia PC
Satellite
Reception
Integrated Receiver
Decoder (IRD)
B-ISDN
ADSL etc.
DVD etc.
DVC etc.
Multichannel
Microwave
Distribution
System (MMDS)
Interactivity
Broadcast

27. Convergence of Application Domains
EPG
Home Shopping
Broadcast TV
PPV
TV with increasing processing
WWW (enhanced features)
WWW (limited graphics)
Internet Telephony
Interactive Multimedia Home Services
Interactivity
Audio on Demand
Video Conferencing
PC with DVB Decoder
Internet Telephony
Full Internet Access (ftp, WWW, , ..)
Interactive PC

28. The Multimedia Home Platform consists of a user terminal including all possible low- to high- functionality implementations, its associated peripherals, and the in-home digital network.
The MHP solution encompasses the whole set of technologies necessary to implement the MHP including protocols, common languages (API), interfaces, and recommendations.
The MHP supports several levels of interactive services / applications. These are defined as:
Enhanced broadcasting (including local interactivity)
Interactive broadcasting (using a return channel)
Internet access

29. Generic SW Interface (API)
The Scope of MHP
Independent developers
Different service providers
Various application areas
Applications
MHP Terminals
Generic SW Interface (API)
Independent implementations
Different hardware
Different software
All kind of terminals (low-end STB / high-end PC)

30. Objectives for Standardization
To deliver bridging between
hardware and software worlds
consumer and computer worlds
existing and future business environment
thus providing an evolution
from today´s fragmented vertical markets
to future unfragmented horizontal markets

31. Some of the key MHP requirements
User friendly
Affordability, appropriate lifetime, interoperability
Designed for all, improving the user experience, customisation
Protecting privacy e.g. no unauthorized access to personal data or parental control signaling
Market friendly
Open standards, Stable, reliable, evolutionary, compatible with CA-systems, Compatible with copy management and content protection
Performing at least as well as proprietary solutions and supporting migration
Innovation friendly
Interactivity, secure transactional services
Internet links and / or full access
Regulation friendly
National or international
e.g. Respect of power consumption strategies

32. Application Oriented Requirements
Enhanced Broadcasting with local interactivity
benchmark applications
built-in navigator
EPG
Interactive Services using a return channel
Internet Access

33. MHP System Definition Equipment (hardware, software)
home terminal / receiver
set top box, integrated TV set, multimedia PC
local cluster
peripherals, in-home digital network
Services / applications (content)
enhanced broadcasting with local interactivity
interactive services using a return channel
internet access

34. An Application Programming Interface (API) is used in a terminal device to implement certain functionalities that allow hardware-independent development of content and applications. It allows differentiation in terms of the capabilities of the end user platform.
The Navigator is the basic user-interface of a terminal device used in the enhanced broadcasting mode. It is defined by the manufacturer of the terminal device. Each MHP provides a Navigator.
The Electronic Program Guide (EPG) is the higher-level consumer navigation device in the enhanced broadcasting mode. It is an application which can be provided by different parties and may be delivered via the broadcast channel.

35. Typical MHP Applications
Electronic program guides
“Super Teletext”
Applications synchronised to TV content
Games
E- commerce
Interactive advertising
Internet access

36. Examples for MHP applications
Electronic Program Guides (EPG)
Information Services (“super teletext”, news tickers, stock tickers)
E-Commerce and Secure Transactions
Applications synchronised to TV Content (score cards, local play-along games)

37. Example of a MHP-based Electronic Program Guide

39. ZDF.vision EPG

40. Application Synchronised to TV Content Golf Game

41. Make a purchase decision
Select a product. Learn more about it.
Make a purchase decision
Easy navigation using scroll bar to select product from range

42. And complete the transaction!

43. Top of the Pops

44. Interactive Advertising
Upon entering enhanced content, video scales.
While viewing, audio/video continue to be available.

45. Airport Information System

46. Airport Information System

47. Technical Specification

48. MHP Specification Overview
Based on DVB-Java
HTML / XML
part of Internet Access profile
Existing (legacy) APIs to be handled as plug-ins

49. Specification Elements (1)
MHP architecture
Detailed profile definition enhanced and interactive broadcasting
Content formats including PNG, JPEG, MPEG-2 Video/Audio, subtitles and resident and downloadable fonts
Mandatory transport protocols including DSM-CC object carousel (broadcast) and IP (return channel),

50. Application Manager (Navigator)
MHP Architecture (1)
Application 1
Applications
Application n
MHP API
Transport Protocols
Virtual Machine
Application Manager (Navigator)
APIs
System Software
Interaction
Channel
MPEG Processing
Graphics
Resources
I/O Devices
Memory
CPU
Broadcast
Channel

51. MHP Architecture (2) CA Applications Cond. Access separated from API L
e.g. Home-
shopping
Appl. 1
e.g. EPG
Appl. n
Applications
Appl. 2
e.g. Game
Cond. Access
separated
from API L O A D E R
A P I
Middleware CA
Operating System
Drivers
Hardware

52. Reference Model of the MHP
The architecture of the MHP is described by 3 layers:
Hardware and Software Resources
System Software
API
Interope-
rable
Applica-
tion 1
tion 2
tion 3
Interop.
tion
Library
Possible
Control

53. MHP summary MHP is very comprehensive system for
applications on digital TV
However, it has not been universally accepted in similar way as teletext. Its
future is thus uncertain.